Initial Preanesthetic Assessment for
1. All patients: Assess exercise tolerance, estimate
predicted postoperative FEV1%, discuss postoperative
analgesia, discontinue smoking
2. Patients with predicted postoperative FEV1< 40%:
DLCO, V/Q scan, VO2 max
3. Cancer patients: consider the “4 Ms”: mass effects,
metabolic effects, metastases, medications
4. COPD patients: Arterial blood gas analysis,
5. Increased renal risk: Measure creatinine and blood
Final Preanesthetic Assessment for
1. Review initial assessment and test results.
2. Assess difficulty of lung isolation: examine
chest radiograph and computed tomography
3. Assess risk of hypoxemia during one-lung
Difficult endobronchial intubation.
• At the time of the preoperative visit, there may be
historical factors or physical findings that lead to
suspicion of difficult endobronchial intubation-
prior pulmonary or airway surgery.
• In addition, there may be a written bronchoscopy
report with detailed description of anatomic features.
• The most useful predictor is the plain chest
• The anesthesiologist should personally view the
chest radiograph before induction of anesthesia
and also examine the CT scan.
• Distal airway problems not detectable on the
plain chest film can sometimes be visualized on
the CT scan
• Ex-a side-to-side compression of the distal
trachea, the so-called saber-sheath trachea, can
cause obstruction of the tracheal lumen of a left-
sided DLT during ventilation of the dependent
lung for a left thoracotomy.
• Similarly, extrinsic compression or intraluminal
obstruction of a mainstem bronchus that can
interfere with endobronchial tube placement may
be evident only on CT .
The left thorax showing tumor
compressing the trachea and pl
Factors That Correlate with an Increased Risk of
Desaturation during One-Lung Ventilation
• High percentage of ventilation or perfusion to
the operative lung on preoperative scan
• Poor PaO2 during two-lung ventilation,
particularly in the lateral position
• Right-sided thoracotomy
• Normal preoperative spirometry (FEV1 or FVC)
or restrictive lung disease
• Supine position during one-lung ventilation
INDICATIONS OF OLV
1. To prevent spillage or contamination
2. Control of distribution of ventilation in BPF,
surgical opening of major bronchus, cyst,
3. Unilateral bronchopulmonary lavage in pul
• A majority of these operations are major procedures of
moderate duration (2-4 hours) and performed in the
lateral position with the hemithorax open.
• Thus, consideration for monitoring and maintenance
of body temperature and fluid volume should be given
to all of these cases.
• Because surgery is usually performed in the lateral
position, monitors will initially be placed with the
patient in the supine position and have to be
rechecked and often repositioned after the patient is
• It is often difficult to add additional monitoring, after
the case is started if complications arise. Choice of
monitoring should be guided by a knowledge of which
complications are likely to occur.
Intraoperative Complications That Occur with Increased
Frequency during Thoracotomy
• SPO2 AND PaO2
• The PaO2 value offers a more useful estimate
• A patient with a two-lung ventilation PaO2 greater than 400
mm Hg with an FIO2 of 1.0 (or an equivalent PaO2/FIO2 ratio)
is unlikely to desaturate during OLV whereas a patient with
a PaO2 of 200 mm Hg is prone to desaturate during OLV,
although both may have SpO2 values of 99% to 100%.
• The rapidity of the fall in PaO2 after the onset of OLV is an
indicator of the risk of subsequent desaturation.
• Measure PaO2 by arterial blood gas analysis before OLV and
20 minutes after the start of OLV.
• During hypoxemia, SpO2 sensor malpositioning can cause
significant underestimation of saturation.
• The end-tidal CO2 (PETCO2) is a less reliable indicator of
the PaCO2 during OLV than during two-lung ventilation.
• The PETCO2 reflects the lung perfusion and cardiac
• As the patient is turned to the lateral position the
PETCO2 of the nondependent lung will fall
1. reflecting increased perfusion of the dependent lung
2. increased dead space of the nondependent lung.
3. The fractional excretion of CO2 will be higher from the
nondependent lung -increased fractional ventilation
of this lung.
• At the onset of OLV -the PETCO2 of the dependent
lung will usually fall transiently as all the minute
ventilation is transferred to this lung.
• The PETCO2 will then rise as the fractional
perfusion is increased to this dependent lung by
collapse and pulmonary vasoconstriction of the
• However, severe (>5 mm Hg) or prolonged falls in
PETCO2 can indicate an maldistribution of
perfusion between ventilated and nonventilated
lungs and may be an early warning of a patient
who will subsequently experience desaturation
• INDICATED-severe hypotension from surgical
compression of the heart or great vessels.
• placement of a radial artery catheter can be in
either the dependent or the nondependent
CENTRAL VENOUS PRESSURE
• The CVP is a useful monitor postoperatively,
particularly for cases in which fluid management is
critical (e.g., pneumonectomies).
• PLACED-pneumonectomy patients but not for lesser
resections unless there is significant other concurrent
• For lobectomies that unforeseeably become
pneumonectomies a CVP catheter is placed at the end
of the operation.
• Our choice is to use the right internal jugular vein to
minimize the risk of pneumothorax for CVP access
unless there is a contraindication.
PULMONARY ARTERY CATHETER
• When left-sided pulmonary artery catheter placement is
required it can be achieved by floating the catheter into the
pulmonary artery when the patient is in the right lateral
• The surgeon can confirm the placement of the pulmonary artery
catheter once the chest is open.
• It is extremely important to remember that a pulmonary artery
catheter ipsilateral to the side of surgery must be withdrawn
before vascular clamping or it could be transected.
• Complications from the use of pulmonary artery catheters
including arrhythmias, hemorrhage, pulmonary infarction.
• If a pulmonary artery catheter is in the nonventilated lung it
frequently becomes accidentally wedged without balloon
inflation as the lung collapses.
• Used only in certain specific cases, such as patients with major
coexisting disease (e.g., cardiac, renal) or having particularly
extensive procedures (e.g., extrapleural pneumonectomy).
• Placement of DLTs or blockers should be
performed with fiberoptic bronchoscopic
guidance and should be reconfirmed after
placing the patient in the surgical position
because a large number of these
tubes/blockers migrate during repositioning of
• The side-stream spirometry -continuously
1. inspiratory and expiratory volumes, pressures,
2. flow interactions during one-lung anesthesia.
3. gives early warning of accidental changes in the
intraoperative position of a DLT
4. the development of auto-PEEP, can also be seen
on the flow-volume loop.
TEE The American Society of Anesthesiologists and Society of Cardiovascular
CATEGORY 1 CATEGORY 2 CATEGORY 3
CARDIAC/ GREAT VESSELS
HEMODYNAMIC INSTABILITY PULMONARY
CARDIAC TAMPONADE AIR EMBOLI
PERICARDIAL EFFUSSION LUNG TRANSPLANT
LUNG ISOLATION TECHNIQUES
• Double-lumen tube
1. Direct laryngoscopy 2. Via tube exchanger 3. Fiberoptically.
• ADVANTAGES-Quickest to place successfully
Repositioning rarely required
Bronchoscopy to isolated lung
Suction to isolated lung
CPAP easily added
Can alternate OLV to either lung easily
Placement still possible if bronchoscopy not available
• DISADVANTAGE-Size selection more difficult
Difficult to place in patients with difficult airways or abnormal tracheas
Not optimal for postoperative ventilation
Potential laryngeal trauma
Potential bronchial trauma
• Bronchial blockers (BB)-
Arndt ,Cohen ,Fuji.
• ADVANTAGE-Size selection rarely an issue
Easily added to regular ETT
Allows ventilation during placement
Easier placement in patients with difficult airways and in
Postoperative two-lung ventilation by withdrawing blocker
Selective lobar lung isolation possible
CPAP to isolated lung possible .
• DISADVANTAGE-More time needed for positioning
Repositioning needed more often
Bronchoscope essential for positioning
Nonoptimal right lung isolation due to RUL anatomy
Bronchoscopy to isolated lung impossible
Minimal suction to isolated lung
Difficult to alternate OLV to either lung
• Univent tube
• ADVANTAGE-Same as BBs
Less repositioning compared with BBs.
• DISADVANTAGE-Same as for BBs
ETT portion has higher air flow resistance than
ETT portion has larger diameter than regular
• Endobronchial tube.
• ADVANATGE-Like regular ETTs, easier placement
in patients with difficult airways
Longer than regular ETT
Short cuff designed for lung isolation .
• DISADVANTGE-Bronchoscopy necessary for
Does not allow for bronchoscopy, suctioning or
CPAP to isolated lung
Difficult right lung OLV
DOUBLE LUMEN TUBE
• 1950-The use of the Carlens design of DLT for lung surgery was a landmark
in the development of thoracic However, the Carlens tube had a high flow
resistance owing to the narrow lumens and also the carinal hook was
difficult to pass through the glottis in some patients.
• In the 1960s, Robertshaw introduced design modifications for separate
left- and right-sided DLTs, removing the carinal hook and using larger
• In the 1980s, manufacturers introduced disposable DLTs made of polyvinyl
chloride based on the design of the Robertshaw DLT.
• Among other subsequent improvements is the inclusion of radiographic
markers near the endotracheal and endobronchial cuffs and a
radiographic marker surrounding the ventilation slot for the right upper
lobe bronchus for the right-sided DLT version.
• Bright blue, low-volume, low-pressure endobronchial cuffs are
incorporated for easier visualization during fiberoptic bronchoscopy.
• A left-sided DLT should have a bronchial tip 1
to 2 mm smaller than the patient's left
bronchus diameter - allow for the space
occupied by the deflated bronchial cuff.
• Chest radiographs and CT scans are valuable
tools for selection of proper DLT size.
SIZE SELECTION ACCORDING TO SEX
SEX HEIGHT (CM) Fr
FEMALES <160 35
FEMALES >160 37
MALES <170 39
MALES > 170 41
AVAILABLE IN SIZES- 26, 28,32, 35,37,39,41
METHOD OF INSERTION
• The DLT is passed with
beyond the vocal cords.
• The DLT should pass
the glottis without any
• The DLT is rotated 90
degrees to the left
• The optimal depth of
insertion -the patient's
height in average-sized
• In adults, depth, measured
at the teeth, for a properly
positioned DLT will be
approximately 12 + (patient
• An inadvertently deep
insertion of a DLT can lead
to serious complications,
including rupture of the left
• The right mainstem bronchus is shorter than the left bronchus
• the right upper lobe bronchus originates at a distance of 1.5 to 2 cm
from the carina, so the right endobronchial intubation can account
for obstruction of the orifice of the right upper lobe bronchus.
• The right-sided DLT incorporates a modified cuff, or slot, on the
endobronchial side that allows ventilation for the right upper lobe.
• Indications for rt sided DLT insertion-
1. Distorted Anatomy of the Entrance of Left Mainstem Bronchus
2. intraluminal tumor compression
3. Descending thoracic aortic aneurysm
4. Site of Surgery Involving the Left Mainstem Bronchus
5. Left lung transplantation
6. Left-sided tracheobronchial disruption
7. Left-sided pneumonectomy
8. Left-sided sleeve resection
Positioning of the DLT
• Auscultation and bronchoscopy should
both be used
• Fiberoptic bronchoscopy is performed
first through the tracheal lumen to
ensure that the endobronchial portion of
the DLT is in the l bronchus and that
there is no bronchial cuff herniation over
the carina after inflation.
• Through the tracheal view, the blue
endobronchial cuff ideally should be
seen approximately 5 mm below the
tracheal carina in the left bronchus.
• identify the takeoff of the right upper
lobe bronchus through the tracheal view.
• Going inside this right upper lobe with
the bronchoscope should reveal three
orifices (apical, anterior, and posterior).
A “three-step” method to confirm
position of a left DLT by auscultation
1. During bilateral
ventilation, the tracheal
cuff is inflated to the
minimal volume that
seals the air leak at the
glottis. Auscultate to
• The tracheal lumen of the
DLT is clamped proximally
and the port distal to the
• During ventilation via the
bronchial lumen the
bronchial cuff is inflated to
the minimal volume that
seals the air leak from the
open tracheal lumen port.
• Auscultate to confirm
correct unilateral ventilation
• 3. The tracheal lumen
clamp is released and
the port closed.
Auscultate to confirm
resumption of bilateral
• malposition and airway trauma.
• A malpositioned DLT will fail to allow collapse of the
lung, causing gas trapping during positive-pressure
ventilation, or it may partially collapse the ventilated or
dependent lung, producing hypoxemia.
• cause of malposition - cuff overinflation, surgical
manipulation of the bronchus, or extension of the head
and neck during or after patient positioning.
If a DLT is in the optimal position, but lung deflation is
not completely achieved, a suction catheter should be
passed to the side where lung collapse is supposed to
occur. This suction will expedite lung deflation.
• Airway trauma
• rupture of the membranous part of the trachea or the
• Airway trauma -oversized DLT or when an undersized
DLT migrates distally into the bronchus .
• Airway damage -air leak, subcutaneous emphysema,
massive airway bleeding into the lumen of the DLT, or
protrusion of the endotracheal or endobronchial cuffs
into the surgical field.
• Tension pneumothorax in the dependent, ventilated,
lung during OLV
DIFFICULT AIRWAY AND OLV
• carcinoma of the pharynx, usually in the epiglottic area.
• previous radiation therapy on the neck
• previous airway surgery, such as hemi-mandibulectomy or
• descending thoracic aortic aneurysm .
• an intraluminal or extraluminal tumor near the tracheobronchial
• SLT placed orally with the aid of a flexible fiberoptic bronchoscope, after
appropriate airway anesthesia is achieved.
• this may be performed after induction of anesthesia with a bronchoscope
or with a videolaryngoscope.
• Once the SLT is in place, an independent bronchial blocker can be passed.
• If the patient requires OLV and cannot be intubated orally, an awake
nasotracheal intubation can be performed with an SLT and, once the
airway is established, then a bronchial blocker can be passed.
• intubate the patient's trachea with an SLT; then a tube-exchange
technique can be used to replace the existing SLT for a DLT after
general anesthesia is induced
• For a DLT the exchange catheter should be at least 83 cm. A 14-Fr
exchange catheter can be used for 41-Fr and 39-Fr DLTs; for 37-Fr or
35-Fr DLTs an 11-Fr exchange catheter is used.
• A sniffing position facilitates tube exchange. After the exchange
catheter is lubricated, it is advanced through an SLT.
• The catheter should not be inserted deeper than 24 cm at the lips
to avoid accidental rupture or laceration of the trachea or bronchi.
• After cuff deflation, the SLT is withdrawn. Then the endobronchial
lumen of the DLT is advanced over the exchange catheter.
• Proper final position of the DLT is then achieved with auscultation
Lung-Isolation Techniques in Patients
with a Tracheostomy in Place
• (1) insertion of an SLT followed by an independent
• (2) the use of a disposable cuffed tracheostomy
cannula with an independent bronchial blocker passed
• (3) replacement of the tracheostomy cannula with a
specially designed short DLT such as the Naruke DLT,
which is made for use in tracheostomized patients
• (4) placement of a small DLT through the
• (5) if possible, oral access to the airway for standard
placement of a DLT or blocker
• It is useful to make an initial “head-to-toe” survey of the patient after
induction and intubation, checking oxygenation, ventilation,
hemodynamics, lines, monitors, and potential nerve injuries.
• Certainly the patient's head, neck, and endobronchial tube should be
turned “en bloc” with the patient's thoracolumbar spine.
• Neurovascular Complications -
• The brachial plexus -The patient should be positioned with padding under
the dependent thorax to keep the weight of the upper body off the
dependent arm brachial plexus.
• Vascular compression of the nondependent arm is possible-monitor pulse
oximetry in the nondependent hand to observe this.
• The arm should not be abducted beyond 90 degrees
• Anterior flexion of the arm at the shoulder (circumduction) across the
chest or lateral flexion of the neck toward the opposite side can cause a
traction injury of the suprascapular nerve.
• This can cause post-thoracotomy shoulder pain.
• The dependent leg - slightly
flexed with padding under the
knee to protect the peroneal
• The nondependent leg is placed
in a neutral extended position
and padding placed between it
and the dependent leg.
• Excessively tight strapping at the
hip level can compress the sciatic
nerve of the nondependent leg.
• Other sites liable injury -are the
dependent ear pinna and eye.
• Lateral position, awake, breathing spontaneously, chest closed
• The distribution of blood flow and ventilation is similar to that in
the upright position, but turned by 90 degrees .
• Blood flow and ventilation to the dependent lung are significantly
greater than to the nondependent lung.
• Good V/Q matching at the level of the dependent lung results in
adequate oxygenation in the awake patient who is breathing
• During spontaneous ventilation, the conserved ability of the
dependent diaphragm to contract results in an adequate
distribution of VT to the dependent lung.
• Because most of the perfusion is to the dependent lung, the V/Q
matching in this position is maintained similar to that in the upright
• Lateral position, awake, breathing spontaneously, chest open
• Two complications can arise –
1. The first is mediastinal shift, usually occurring during inspiration
negative pressure in the intact hemithorax
the mediastinum to move vertically downward and push into the
The mediastinal shift can create circulatory and reflex changes that
may result in a clinical picture similar to that of shock and
2. paradoxical breathing .
During inspiration, the relatively negative pressure in the intact
hemithorax compared with atmospheric pressure in the open
movement of air from the nondependent lung into the dependent
The opposite occurs during expiration.
This gas movement reversal from one lung to the other represents
wasted ventilation and can compromise the adequacy of gas
Positive-pressure ventilation or adequate sealing of the open chest
eliminates paradoxical breathing
• Lateral position, anesthetized, breathing spontaneously, chest
• VT enters the nondependent lung, and this results in a significant
• reduction in FRC.
• the cephalad displacement of the dependent diaphragm by the
abdominal contents is more pronounced and is increased by
• the mediastinal structures pressing on the dependent lung or poor
positioning of the dependent side on the operating table prevents
the lung from expanding properly.
• The nondependent lung moves to a steeper position on the
compliance curve and receives most of the VT, whereas the
dependent lung is on the flat (noncompliant) part of the curve
Lateral position, anesthetized, paralyzed, chest
• During paralysis and positive-pressure ventilation,
diaphragmatic displacement is maximal over the
nondependent lung, where there is the least
amount of resistance to diaphragmatic
• This further compromises the ventilation to the
dependent lung and increases the V/Q mismatch.
One-lung ventilation, anesthetized, paralyzed, chest open
• During two-lung ventilation in the lateral position, the
mean blood flow to the nondependent lung is assumed to
be 40% of cardiac output,
• whereas 60% of cardiac output goes to the dependent lung
• venous admixture (shunt) in the lateral position is 10% of
cardiac output and is equally divided as 5% in each lung.
• Therefore, the average percentage of cardiac output
participating in gas exchange is 35% in the nondependent
lung and 55% in the dependent lung.
• OLV creates an obligatory right-to-left transpulmonary
shunt because the V/Q ratio of that lung is zero.
• active HPV, blood flow to the nondependent hypoxic
lung will be decreased by 50% and therefore is (35/2) =
17.5%. To this, 5% must be added, which is the
obligatory shunt through the nondependent lung. The
shunt through the nondependent lung is therefore
• Together with the 5% shunt in the dependent lung,
total shunt during OLV is 22.5% + 5% = 27.5%. This
results in a Pao2 of approximately 150 mm Hg (FIO2 =
• Because 72.5% of the perfusion is directed to the
dependent lung during OLV, the matching of ventilation
in this lung is important for adequate gas exchange.
• There are several reasons for reduction in FRC,
1. including general anesthesia, paralysis,
2. pressure from abdominal contents,
3. compression by the weight of mediastinal structures,
4. suboptimal positioning
6. accumulation of secretions
7. formation of a fluid transudate in the dependent lung.
All these create a low V/Q ratio and a large P(A-a)o2
• Fluid Management
subsequently lead to pulmonary edema of the dependent lung.
• judicious fluid administration.
• Intravenous fluids are administered to replace volume deficits and
for maintenance only during lung resection anesthesia.
• No volume is given for theoretical “third space” losses during
• The commonly accepted dictum is “don't drown the down lung.”
1. Total positive fluid balance in the first 24-hour
perioperative period should not exceed 20 mL/kg.
2. For an average adult patient, crystalloid
administration should be limited to < 3 L in the first 24
3. There should be no fluid administration for third
space fluid losses during pulmonary resection.
4. Urine output > 0.5 mL/kg/hr is unnecessary.
5. If increased tissue perfusion is needed
postoperatively, it is preferable to use invasive
monitoring and inotropes rather than to cause fluid
N2O AND TEMPERATURE
• Nitrous oxide/oxygen (N2O/O2) mixtures are more prone to cause
• The rate of uptake of an N2O/O2 mixture from an unventilated lung
exceeds that of pure oxygen.
• Nitrous oxide also tends to increase pulmonary artery pressures in
patients who have pulmonary hypertension.
• N2O inhibits HPV ,and N2O is contraindicated in patients with blebs
or bullae. For these reasons N2O is usually avoided during thoracic
• heat loss from the open hemithorax.
• HPV, are inhibited during hypothermia.
• Increasing the ambient room temperature, fluid warmers, and the
use of lower- or upper-body forced-air patient warmers methods to
prevent inadvertent intraoperative hypothermia.
• HPV -governs the redistribution of blood flow during
• It decreases the blood flow to the nonventilated lung
• The stimulus is alveolar oxygen tension (PAO2), which
stimulates precapillary vasoconstriction redistributing
pulmonary blood flow away from hypoxemic lung
regions via a pathway involving NO and/or
cyclooxygenase synthesis inhibition.[
• HPV starts over the first 30 minutes and then a slower
increase to a maximal response at approximately 2
Factors affecting HPV
• The surgical trauma
• Surgery may oppose HPV by release of
• HPV is decreased by vasodilators such as
nitroglycerin and nitroprusside
• Thoracic epidural sympathetic blockade
probably has little or no direct effect on HPV
CHOICE OF ANESTHETICS
• All of the volatile anesthetics inhibit HPV in a
• The older agents were potent inhibitors of
• In doses less than or equal to 1 MAC, the
modern volatile anesthetics (isoflurane,
sevoflurane, and desflurane) are weak, and
equipotent, inhibitors of HPV.
• Tidal volume- 5-6 mL/kg
• Peak airway pressure < 35 cm H2O
• Plateau airway pressure < 25 cm H2O.
• Positive end-expiratory pressure 5 cm H2O Patients
with COPD: no added PEEP.
• Respiratory rate 12 breaths/min & Maintain normal
• Mode Volume or pressure controlled .Pressure control
for patients at risk of lung injury (e.g., bullae,
pneumonectomy, post lung transplantation)
THERAPIES OF HYPOXEMIA
• During OLV there will be a fall in arterial
oxygenation by 20 to 30 minutes after the
initiation of OLV
• then the saturation will stabilize or may rise
slightly as HPV increases over the next 2 hours.
• A majority of patients who desaturate do so
quickly and within the first 10 minutes of OLV.
Hypoxemia during OLV responds readily to
treatment in the vast majority of cases.
1. Resume two-lung ventilation. Reinflate the
nonventilated lung and deflate the bronchial
cuff of the double lumen tube or the
2. Increase FIO2. Ensure that the delivered FIO2
3. Recheck the position of the DLT or bronchial
blocker. Ensure that there is no lobar
obstruction in the ventilated lung.
• 4. Check the patient's hemodynamics to
ensure that there has been no decrease in
cardiac output Treat the fall in cardiac output
as indicated (e.g., inotropes/vasopressors if
due to thoracic epidural sympathetic
• Stop administration of vasodilators, and
decrease MAC of volatile anesthetics to less
than or equal to 1 MAC.
• CPAP- 5-10cms of H2O can be applied to the
non- dependant lung,this allows some gas
exchange in the non-dependant lung.
• PEEP-5-10cms of H2O can be applied to the
dependant lung, this shifts it to the more
complaint part of the pressure volume curve.
• CPAP &PEEP can be gradually in increments of
5cms as long the pts hemodynamic status
• Thoracic epidural –gold std
• Local anesthetic are given via a patient control device
• Parenteral opioids- via pt control analgesia & are
considered to be superior to IM/Ivopioids
• Paravertebral blocks- intercostal nerves, unilateral
analgesia, lesser side effects.
• Intrathecal oipoids- preservative free morphine can be
injected into the SAB at lumbar level, causes rostral
• Intercostal nerve blocks- blocked above & below the
surgical incision but it is short acting.
Cvs- arrhythmias,Rt ventricular failure,Cardiac
Pulmonary- pul edema, respiratory insufficiency,
Pneumonectomy space- BP fistula, empyema
Neurological- RLN, vagus and phrenic nerve